They should get retroactive refunds. The debate on same sex marriage has been a long one. No need to keep causing more delays. One time retroactive payment and done. This is a mere fraction of the overall revenue.
For anyone with an issue with same-sex marriage, if you don’t like it, don’t be in one. They won’t tell you how you should live your life, so you shouldn’t tell them how they should live theirs. If you are under this opinion due to your religious beliefs, than that is your belief and not the same as theirs. The government isn’t a church and should not segregate based on beliefs. It is merely there to manage the benefits for all and protects the rights of the people.